Toyota Venza: System Description

Toyota Venza Service Manual / Brake Control / Dynamic Control Systems / Vehicle Stability Control System / System Description

SYSTEM DESCRIPTION

1. FUNCTION DESCRIPTION

(a) Steering Cooperative Control

(1) Enhanced-VSC performs coordinated control consisting of VSC and electronic power steering. By integrating these preventive safety functions, Enhanced-VSC ensures excellent driving stability and maneuverability of the vehicle.

(b) Anti-lock Brake System (ABS)

(1) The ABS helps prevent the wheels from locking when the brakes are applied firmly or when braking on a slippery surface.

(1) The EBD control utilizes the ABS, and performs proper brake force distribution between the front and rear wheels in accordance with driving conditions.

When braking while cornering, it also controls the brake forces of the right and left wheels, helping to maintain vehicle behavior.

(d) Brake Assist (BA)

(1) The primary purpose of the brake assist system is to provide auxiliary brake force to assist a driver who cannot generate a large enough brake force during emergency braking, thus helping to maximize the brake performance of the vehicle.

(e) Traction Control (TRAC)

(1) The TRAC system helps prevent the drive wheels from slipping when the driver depresses the accelerator pedal excessively when starting off or accelerating on a slippery surface.

(f) Vehicle Stability Control (VSC)

(1) The VSC system helps prevent the vehicle from slipping sideways as a result of strong front or rear wheel skid during cornering.

(g) Hill-start Assist Control

(1) When the vehicle starts off on a steep or a slippery hill, hill-start assist control detects the backward movement of the vehicle and effects four-wheel hydraulic pressure control to prevents the vehicle from moving backward.

2. FUNCTION OF COMPONENTS

Component		Function
Brake actuator assembly	Skid control ECU	Judges the vehicle driving condition based on the signals from each sensor, and sends the brake control signals to the brake actuator.
	Master cylinder pressure sensor	Assembled in the brake actuator, detects the master cylinder pressure.
	ABS motor relay	Supplies power to the pump motor.
	ABS solenoid relay	Supplies power to the solenoid valves.
	Solenoid valves	Change the fluid path based on the signals from the skid control ECU during the operation of the brake control system functions in order to control the fluid pressure applied to each wheel cylinder.
Speed sensor		Detects the wheel speed of each of the four wheels.
VSC OFF switch		Enables the driver to select normal mode, TRAC off mode or VSC off mode.
Brake pedal load sensing switch		Detects the brake pedal depressing force.
Stop light switch		Detects brake pedal operation.
Stop light control (BRK) relay		Illuminates the stop lights when hill-start assist control is operating.
Steering angle sensor		Detects the direction and angle of the steering wheel.
Yaw rate and acceleration sensor		Detects the vehicle's longitudinal and lateral acceleration and deceleration. Detects the vehicle's yaw rate.
Main body ECU (Driver side junction block)		Detects the parking brake signal and outputs it to the skid control ECU via CAN communication.
ECM		Sends the throttle position signal, accelerator pedal position signal, engine speed signal etc., to the skid control ECU. Based on the signals received from the skid control ECU, controls the engine output.
Combination meter	ABS warning light	Illuminates to alert the driver when the skid control ECU detects a malfunction in the ABS or BA.
	Brake warning light	Illuminates to alert the driver when the skid control ECU detects a malfunction in the EBD. Illuminates to alert the driver when the skid control ECU detects a malfunction in the brake booster. Illuminates to alert the driver when the brake fluid level is low. Illuminates to inform the driver when the parking brake is applied.
	Meter buzzer	Emits a warning sound to inform the driver at the beginning and completion of hill-start assist control operation.
Accessory meter	TRAC OFF indicator light	Illuminates to inform the driver when the TRAC off mode is selected.
	VSC OFF indicator light	Illuminates to inform the driver when the VSC off mode is selected.
	Slip indicator light	Blinks to inform the driver when TRAC or VSC is operating. Illuminates to alert the driver when the skid control ECU detects a malfunction in the TRAC or VSC.
	Master warning light*1	Illuminates to alert the driver when the skid control ECU detects a malfunction in the brake control system.
	Multi-information display*2	Displays a warning message to alert the driver when the skid control ECU detects a malfunction in the brake control function.

*1: w/ master warning light

*2: w/ rear view monitor system

Parts Location

PARTS LOCATION ILLUSTRATION ILLUSTRATION ...

System Diagram

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